Valve-gear for engines.



PATENTED AUG. 1a

D. MAoLAUHI-AN. VALVE GEAR FOR menus;

APPLIGATION ILLBI JAN. 10, 1905.'

3 SHEETS-SHEET 1'.

No. 863,545. PATENTED AUG. 13, 190?. J. n. MAOLAGHLAN.

VALVE GEAR FOR ENGINES.

APPLICATION FILED 31111.10, 1905.

- s SHEETS-SHEET 2.

No. 863,545. PATENTED AUGIlS, 1907. J. D. MAQLACHLAN.

. VALVE GEAR FOR ENGINES.

APPLIOATION FILED JAN. 10. 1905.

'3 SREETS-SHBET a.

Hill

:WIITNEISSES: IINVENTOR UNITED STATES PATENT OFFICE.

JOHN D. MACLAGHLAN, 0F DETROIT, MICHIGAN, ASSIGNOR TO DETROIT STEAM ENGINE COMPANY.

VALUE-GEAR FOR ENGINES.

Specification of Letters Patent.

Patented Aug. 13, 1907.

Application filed January 10,1905. Serial No. 240,482.

To all whom it may concern: Be it known that I, JO N D. MAcLAcHLAN, residing at Detroit, in the county of Wayne and State of Michigan, a citizen of the United States, have invented certain newand useful Improvements in Valve-Gear for Engines, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention relates to steam engines. The objects of my invention are to 'produce an engine embodying features of simplicity, compactness, strength and cheapness of construction.

A-further object is to actuate the inlet and exhaust valves by independent cam shafts, whereby independent timing of the inlet and egrhaust valves may be at;

tained and wear reduced. Other objects are to so organize the engine that the valve-actuating cams may operatein direct alinement with the valves and valve stems; and to so locate the inlet and exhaust valves relatively to the cylinder that clearance space can be reduced to a minimum and a single passage may be utilized for both steam andexhaust To these ends, therefore, my invention consists in certain novel features and combinations of parts, all of which will be more fully set forth hereinafter and particularly pointed out in the claims. i

In the accompanying drawings, Figure l. is a part sectional side elevation. Fig. 2 is a vertical cross sectional view taken through one of the cylinders. Fig. 3 is a top plan view of the cam shifting mechanism.

Asshown, A indicates the cylinders mounted on the crank base (R). Iihave illustrated an engine comprising four cylinders,,th e upper parts of which are jacketed as at (B, G), the jacket having the outlets (D, K). As the cylinders arealike, a description of one will sufice for all. I i

' The cylinder (A) is provided with an exhaust port (E) communicating with the jacket (B, O). The piston I suchas shown, the chests (H) are connected by a suitable passage (1) having an inlet (J). The inlet valve 3 chest (H) is located at one side of the cylinder, as 5 shown in Figs. 1 and 2, and the corresponding exhaust valve chest (H) is located at the other side. The exhaust valve chests are connected by an exhaustpassage (I) communicating with the jacket (B O) The passage (L) formed in the head (G) connects the inlet and exhaust valve chests of one cylinder. An opening (M) in the cylinder head connects each cross passage (L) with its cylinder.

N is a steam valve and N is an exhaust valve, both being of the straight lift or puppet type and located in the respective valve chests (H) (11). Each valve is provided with a vertical stem (0) passing downward through a packing gland (P) and encircled by acompression spring (Q) ads oted to retain the valve normally in its seat.

Located within the crank base and parallel with each other are the valve actuating cam shafts (U) (U). The cam shafts lie on opposite sides of the crank base and directly beneath their cdrresponding valve stems. Interposed between the cam shaft and the lower ends of the valve stems (O) are vertical sliding rods (X) (X) coaxial with the valve stems. These rods are carried by suitable guides (X) (X) and each rod is provided at its lower end with a hardened steel ball (X The guides (X) (X) are removably mounted on the crank base (R). The crankshaft (S) is suitably journaled in the,,vrirank base (R), the shaft being provided with cranks (8) connected by piston rods (T) to the pistons (F). Each cam shaft is connected by av train of gears.

(W) with the crank shaft (S) in such manner that the cam shafts rotate in the same direction as the-crank shaft a d preferably at the same speed. I prefer to operate the exhaust cam shaft (U) by means of a train of gearsllocated at one end of the crank base as shown at the left in Fig. 3, and the cam shaft (U) operating the steam inlet valve (H) by a train of gears located at the right in Fig. 3. The .cam shafts are longitudinally slidable in bearings (V) (V) at opposite ends of the base (R), as shown in Figs. 1 and 3.

The cams (Y) are preferably arranged in pairs as at (1), (2) on shaft (U). Longitudinal shifting ofthe cam shaft (U) in the bearings (V) brings either cam (l) or (2) into action with the rod (X). The two earn shafts (U) and (U) are moved lengthw ise simultaneously, being connected at their outer ends by a yoke (1')) held in place by collars (a) or other suitable means. The yoke (b) isactuated by a lever (c) pivoted to a suitable bracket (d). It will be understood that the cams are of suitable fonn togive the proper amount of opening and closing and the proper duration of opening and closing to the valves. The actual time of opening and closing the valves is, however, controlled by the longitudirral movement of the independent cam shafts.

By arranging the valve, valve stem and rod (X) in co axial alinement and locating thecam directlybeneath and in engagement with the rod. (X), I eliniinate 100 red (X) and to the valve. Hence the valve may be of comparatively small area on account of the higher respectively, islthat either (cam shait can be angular-1y 1 10 lift imparted by the cam, as distinguished from a cam 1. In a steam englne,-the combination with the cylinder,

crank base. and crank shaft; of a pair of cum shafts located in the base and rotated by the crank siiaft,'inlct 'cnmsun one cam shaft, exhaust cams on the opposite cam shaft, vertically slidable valve-actuating rods mount ed in the base, their lower ends being in register with their respective cams: valve stems coaxial with the .valve actuating rods. the upper ends of the valve actuating: rcds adapted to impinge directly against the lower ends of the valve stems; inlet valves seated in the cylinder head at one side of the cylinder and actuated by the inlet cams; exhaust valves seated in the cylinder head at the opposite side of the cylinder and actuated by the exhaust rams; together with a yoke located outside the crank base and connecting the two cam shafts to move them in or out simultaneously.

2. In a steam engine, means for actuating the inlet and exhaust valves, comprising a pair of independent inlet and exhaust cam shafts located in the crank base of the engine, means for rotating the cam shafts simultaneously, and a flyohe outside the crank base, said yoke connectin the two cam shafts to move them. in or out simultaneously.

3. In a steam engine. means for actuating the inlet and exhaust valves, comprising a pair of independent inlet I and exhaust cam shafts located in the crank base of the engine; a train of gears located at one end of the crank base for rotatlvely connecting the inlet cam shaft and the crank shaft; a train of gears located at the opposite end of the crank base for rotatively connecting the ex ha'ust cam shaft with the crank shaft; and a yoke located outside the crank base, said yoke connecting the two cam shafts to move them in or out simultaneously.

4. in a steam engine provided with inlet and exhaust valves, means for actuating the inlet and exhaust valves, comprising a pair of independent inlet and erg haust cam shafts located in the crank base of the engine, and means operable from without the crank hase engaging the cam shafts to move them simultaneously and longitddinally.

5. In a steam engine provided with inlet and exhaust comprising a pair of independent inlet and exhaust csni shafts located in the crank base of the engine, means for rotating the cam shafts slmultaneously'and means engaging the two cam shafts for moving them simultaneously in i1 longitudinal direction.

6. In a steam engine provided with inlet and exhaust valves, means for actuating the inlet and exhaust valves, comprising a' pair of independent inlet and exhaust cam shafts located in the crank base of the engine, means for rotating the cam shafts simultaneously and means located and operated outside the crank base and engaging the cam shafts to move them simultaneously and longitudinally.

In testimony whereof I aflix my signature in presence of two witnesses. i

JOHN D. MACLACHLAN.

Witnesses H. C. SMITH, .Ins. P. BARRY.

valves, means for actuating the inlet and exhaust valves. 

